Content disposition duplicate headers solution for google chrome

Recently I had a problem while serving dynamic content in a Spring MVC application; (more details here) when attempting to open some of the dynamic content with Chrome I was having a weird error message :

Duplicate headers received from server The response from the server contained duplicate headers. This problem is generally the result of a misconfigured website or proxy. Only the website or proxy administrator can fix this issue. Error 349 (net::ERR_RESPONSE_HEADERS_MULTIPLE_CONTENT_DISPOSITION): Multiple distinct Content-Disposition headers received. This is disallowed to protect against HTTP response splitting attacks.

I wasn't sure why I was having this problem, since some dynamic content was working properly and I was setting only once the Content-Disposition header on my code

So after searching around a bit I stumbled upon the HTTP specs it turns out the Content-Disposition header should not contain a coma since it will be treated as a header separator

Multiple message-header fields with the same field-name MAY be present in a message if and only if the entire field-value for that header field is defined as a comma-separated list [i.e., #(values)]. It MUST be possible to combine the multiple header fields into one "field-name: field-value" pair, without changing the semantics of the message, by appending each subsequent field-value to the first, each separated by a comma.

Personally I decided to create slugs for all my file names using the Slugify library :

slugify dependency

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<dependency>     <groupid>com.github.slugify</groupid>     <artifactid>slugify</artifactid>     <version>2.1.3</version> </dependency>

slugify fileName

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public String slugify(String originalFileName){       String extension = FilenameUtils.getExtension(originalFileName);     return new Slugify(true).slugify(FilenameUtils.removeExtension(originalFileName)) +"."+extension;;   }

Spring mvc send binary content from controller

Sometimes binary files such as images, documents are stored in the database; these binary files need then to be served dynamically

Below I'll show a code snippet showing how to handle this easily with Spring MVC

Before we begin just in case this is the list of libraries I used when coding this example :

• Spring 3+
• Spring Data JPA
• Eclipselink 2.4+
• Apache Tika
• Slugify

Resource class

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@Entity public class Resouce{       @Id @Column(name = "ID")     @GeneratedValue(strategy = GenerationType.IDENTITY)     private Long id;       @Column(name = "FILE_NAME", length = 200)     private String fileName;        @Column(name = "FILE")     @Lob     private byte[] file;      //SETTERS - GETTERS OMMITED }

404 exception

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@ResponseStatus(value = HttpStatus.NOT_FOUND) public class ResourceNotFoundException extends RuntimeException {   }

controller

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/**  * @author ulf  */ @Controller @RequestMapping("/resource") public class ResourceController{       // a basic Spring data repository     @Autowired     private ResourceRepostiory resourceRepository;             // simple tika instance for handling mimetype resolution     @Autowired     private Tika tika;       @RequestMapping(method = RequestMethod.GET)     public ResponseEntity<byte[]> resource(@RequestParam("resourceId") Long resourceId) throws IOException {           byte[] binary = null;         String fileName = "";                 Resouce resource= resourceRepository.findOne(resourceId);               if (resource!= null  && section.getFile() !=null ) {                 binary = section.getFile();                 fileName = section.getFileName();             }             if (binary == null) {             throw new ResourceNotFoundException();         } else {               String extension = FilenameUtils.getExtension(fileName);               // slugify the fileName to handle the Google Chrome error complaining of duplicate content disposition headers whenever the file name contains a ,             fileName = new Slugify(true).slugify(FilenameUtils.removeExtension(fileName)) +"."+extension;               HttpHeaders headers = new HttpHeaders();             headers.setContentType(MediaType.parseMediaType(mimetype(fileName)));             headers.setContentDispositionFormData(fileName, fileName);             headers.setCacheControl("must-revalidate, post-check=0, pre-check=0");             ResponseEntity<byte[]> responseEntity = new ResponseEntity<byte[]>(binary, headers, HttpStatus.OK);             return responseEntity;             }         }       private String mimetype(String fileName) {         return ConfigurableMimeFileTypeMap.getDefaultFileTypeMap().getContentType(fileName);     }     }     </byte[]></byte[]></byte[]>

And that's it you should now be able to serve resources dynamically based on their id